REVIEWTOMERGE-project-board-updates

https://github.com/rust-lang/rust/issues/34472
https://github.com/rust-lang/rust/issues/36749
https://github.com/rust-lang/rust/issues/37179
https://github.com/rust-lang/rust/issues/43354
https://github.com/rust-lang/rust/issues/37634
https://github.com/rust-lang/rust/issues/37871
https://github.com/rust-lang/rust/issues/41407
https://github.com/rust-lang/rust/issues/42154
https://github.com/rust-lang/rust/issues/51588
https://github.com/rust-lang/rust/issues/30974
https://github.com/rust-lang/rust/issues/49129
https://github.com/rust-lang/rust/issues/54144
https://github.com/rust-lang/rust/issues/51125
https://github.com/rust-lang/rust/issues/54889
https://github.com/rust-lang/rust/issues/40322